1. Field of the Invention
The invention pertains to the art of printing documents from a computer and, more particularly, to a front end software module for improving the use of system resources during printing.
2. Description of Related Art
When a document on the screen of a computer is to be printed, a protocol module such as AppleTalk by Apple Computer is used to facilitate communication between the compute the network and print devices. The data containing the print commands and the information to be printed is sent over the network encoded in a page description language such Postscript from Adobe, Inc. The data is translated at the print device by an Interpreter for the page description language in which it is encoded such as a Postscript Interpreter. The interpreter translates the data received into commands which the printer uses to produce the resulting document.
When a client sends a job to be printed, the AppleTalk protocol sends some initial data to the Postscript interpreter and waits for a response before proceeding to deliver the rest of the print data. When a page printer has been used, the operation has functioned smoothly. A page printer takes in one stream of data, which is parsed one page at a time. As a result, the page printer is able to quickly provide the response required by the AppleTalk protocol.
However, when a job printer is used, significant delays for the computer sending the print job, known as the client, arise. In a job printer, a job manager queues jobs received simultaneously over multiple incoming streams. In this case one or more entire print jobs will be parsed before a response is sent to the AppleTalk Client. When client computers are networked together and there is only one or just a few print devices, multiple data streams are sent to the print device and are queued up for the interpreter. Print jobs often become backlogged and the AppleTalk module for any given client will not promptly receive the required response, causing the client machine to wait for the response. While the client computer is waiting, no other functions can be performed, thus creating significant time periods of inoperation for a computer user.
The present invention contemplates a new apparatus and method for providing a response to the AppleTalk module without the intervention of the Postscript interpreter, resulting in a significant reduction of the response time to the client in a job printing system.